The Carpometacarpal (Thumb) Joint

Question 1

Classification of the carpometacarpal joint.

Answer 1

Synovial saddle joint

Question 2

The carpometacarpal joint is an articulation between…

Answer 2

The base of the first metacarpal and the trapezium.

Question 3

Name & describe the articular surfaces of the carpometacarpal joint.

Answer 3

Trapezium - Concave & convex perpendicular to this
Base of 1st metacarpal - reciprocal curvatures

Question 4

Describe the joint capsule of the carpometacarpal joint

Answer 4

Loose yet strong fibrous capsule.
Completely encloses the joint.
Attaches to the articular margins of both bones.

Question 5

Name the ligaments present in the carpometacarpal joint

Answer 5

Radial carpometacarpal ligament.
Anterior and posterior oblique ligaments.

Question 6

The radial carpometacarpal ligament attachments.

Answer 6

Passes the lateral surface of the trapezium and first metacarpal.

Question 7

Anterior and posterior oblique ligaments attachments.

Answer 7

pass from the anterior or posterior aspect of the trapezium to the medial side of the first metacarpal, converging as they do

Question 8

What movement does the posterior oblique ligament limit?

Answer 8

flexion

Question 9

What movement does the anterior oblique ligament limit?

Answer 9

extension

Question 10

Name the movements possible at the thumb.

Answer 10

Flexion extension abduction adduction opposition.

Question 11

Describe flexion and extension at the thumb.

Answer 11

Occurs in the plane of the palm in the anatomical position.
Total range = 40 to 50 degrees.

Question 12

Describe abduction and adduction in the thumb.

Answer 12

Occurs at right angles to the palm total range = 80 degrees.

Question 13

Describe opposition at the thumb

Answer 13

Distal part of the thumb to the distal part of any of the four digits and is a combination of movements.